diff --git a/libraries/AP_GPS/AP_GPS_NMEA.cpp b/libraries/AP_GPS/AP_GPS_NMEA.cpp
index 9c467a5dfe..de4dd36b0c 100644
--- a/libraries/AP_GPS/AP_GPS_NMEA.cpp
+++ b/libraries/AP_GPS/AP_GPS_NMEA.cpp
@@ -389,7 +389,7 @@ bool AP_GPS_NMEA::_term_complete()
                         state.ground_speed = state.velocity.xy().length();
                         _last_3D_velocity_ms = now;
                     }
-                    if (is_equal(3.0f, _ksxt.fields[10])) {
+                    if (is_equal(3.0f, float(_ksxt.fields[10]))) {
                         // have good yaw (from RTK fixed moving baseline solution)
                         _last_yaw_ms = now;
                         state.gps_yaw = _ksxt.fields[4];
diff --git a/libraries/AP_GPS/AP_GPS_NMEA.h b/libraries/AP_GPS/AP_GPS_NMEA.h
index c03d29df7f..70b1d5f172 100644
--- a/libraries/AP_GPS/AP_GPS_NMEA.h
+++ b/libraries/AP_GPS/AP_GPS_NMEA.h
@@ -188,7 +188,7 @@ private:
       example: $KSXT,20211016083433.00,116.31296102,39.95817066,49.4911,223.57,-11.32,330.19,0.024,,1,3,28,27,,,,-0.012,0.021,0.020,,*2D
      */
     struct {
-        float fields[21];
+        double fields[21];
     } _ksxt;
 
 };